One type of paper commonly handled by computer printers has a web of many sheets joined end to end and joined along the sides with holed edge portions. This web is fed through the printer with the help of a pin-feed system, is printed on, and then must be separated into individual sheets. The holed edge portions of each sheet are separated from the main body by score lines or perforated lines, so that the holed edge portions can be separated from the printed area along these lines. The holed edge portions are usually, but not always, removed by hand. When one page or many pages are printed in one job, the tearing and stripping of the edge portions from the paper can be a laborious task. The side edges must also be removed from the last printed sheet, which typically requires the advancement of the paper roll to permit proper gripping. An unprinted sheet, however, must usually be advanced past the printing area to permit this process, which then requires either the back-rolling of the paper or the waste of an unprinted sheet.
It would be advantageous to provide some means of automatically stripping the holed edge portions of the paper before the paper reaches the printing area, or at the printing area.
Eudy, U.S. Pat. No. 5,190,386, and Lund, U.S. Pat. No. 5,120,144 show printers with edge strip trimmers mounted on the tractor feed clips, past the printing area, used in many printers to hold the paper on the tractor feed sprocket wheels. Chung, U.S. Pat. No. 4,993,856, shows another type of edge strip trimmer mounted on the base for the tractor feed sprocket.
Generally, the prior art has provided edge strip trimmers that are relatively complex and difficult for a user to attach, or are specially adapted to a particular machine. There is the further problem of replacing blades in these devices. Also, these prior art devices mount the strip trimmers past the printing area, and therefore still require back-rolling of the paper, or the waste of a sheet of paper, in order to remove a printed sheet that has been completely trimmed.
There is a need in the art for an inexpensive, easy-to-install and remove edge strip trimmer, mountable on a variety of printers and tractor feed systems.